The application and dispensing of various dental materials directly to a tooth surface during a tooth restoration or cosmetic procedure has been known for some time. The application and placement of dental materials directly to the site of the restoration or procedure using a syringe technique is disclosed in U.S. Pat. Nos. 3,581,399; 3,900,954; 4,198,756 and Design Pat. No. 224,655. These patents disclose the syringing technique of utilizing a unit dose capsule formed of a suitable plastic material having a reservoir for containing a predetermined amount of dental material having a discharge end or nozzle through which the dental material is extruded by the displacement of a piston sealing the open end of the capsule.
Subsequently, others attempted to duplicate the technique of placing dental materials to the site of the procedure, using only slightly modified constructions, such as evidenced by U.S. Pat. Nos. 4,330,280; 4,391,590; and 5,707,234. These later issued patents disclose a capsule design similar to the earlier issued Dragan patents, but differing therefrom in that the closed end of the capsule was provided with a known hemispherical shape.
As the syringing technique and the use of unit dose capsules for dispensing dental material gained recognition as a preferred method of placing dental material within the dental profession, various other capsule configurations have been made as evidenced by U.S. Pat. No. 4,619,613; DES Pat. No. 292,825; 4,963,093; 4,969,816; DES Pat. No. 315,956; U.S. Pat. No. 5,052,927; 5,083,921; 5,122,057; 5,129,825; 5,165,890; 5,172,807; 5,267,859; 5,324,273; 5,336,088, and DES Pat. No. 359,119. Reference is also made to the capsule construction of U.S. Pat. No. 5,460,523 assigned to Jeneric/Pentron, which appears to be a mere variation of the capsules of the previously noted patented constructions.
The foregoing noted patented constructions are essentially directed to a capsule body having a reservoir for containing a predetermined amount of dental material having a discharge nozzle at one end and a flange circumscribing an opening at the other end, and through which the material is loaded into the capsule, after which the opening is sealed by a displaceable piston for expressing the material in the reservoir through the discharge nozzle as the piston is displaced by a syringe applicator.
A further variation of dental capsules is evidenced in U.S. Pat. No. 4,578,055; 4,997,371; and 5,246,371. These patents are directed to a dental tip or capsules having a body portion terminating in a discharge nozzle in which a strand of bristles are slidably secured within the discharge nozzle so that the bristles may be pushed into and out of the discharge nozzle for applying a dental material to either a small or large area accordingly. It has been noted that the strand of bristles located internally of the discharge opening constitute an obstruction to the flow of dental material therethrough. A further limitation noted with the constructions of the latter identified patents is that the bristles are unidirectional so that the dental material can be applied only at the tip end of the bristles. Also, the insertion of a stand of bristles into the relatively small orifice of the discharge opening requires a tedious, time consuming and a relatively expensive procedure.
Various types of brush applicators for applying a dental material to a tooth are also known, as evidenced by U.S. Pat. Nos. 5,001,803; 5,150,495 and German Patent DE 3937030. However, such brush type applicators have the disadvantage that the brush must be repeatedly dipped into the dental material being applied, which may constitute a source of cross contamination and/or waste of dental material.